Class: Nokogiri::CSS::XPathVisitor

Inherits:
Object
  • Object
show all
Defined in:
lib/nokogiri/css/xpath_visitor.rb

Instance Method Summary collapse

Instance Method Details

#accept(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 132

def accept node
  node.accept(self)
end

#visit_attribute_condition(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 50

def visit_attribute_condition node
  attribute = if (node.value.first.type == :FUNCTION) or (node.value.first.value.first =~ /^@/)
                ''
              else
                'child::'
              end
  attribute += node.value.first.accept(self)

  # Support non-standard css
  attribute.gsub!(/^@@/, '@')

  return attribute unless node.value.length == 3

  value = node.value.last
  value = "'#{value}'" if value !~ /^['"]/

  case node.value[1]
  when '*='
    "contains(#{attribute}, #{value})"
  when '~='
    [ "#{attribute} = #{value}",
      "starts-with(#{attribute}, concat(#{value}, \" \"))",
      "contains(#{attribute}, concat(\" \", #{value}, \" \"))",
      "(substring(#{attribute}, string-length(#{attribute}) - " +
        "string-length(#{value}), string-length(#{value}) + 1) = concat(\" \", #{value}))"
    ].join(' or ')
  when '$='
    "substring(#{attribute}, string-length(#{attribute}) - " +
      "string-length(#{value}) + 1, string-length(#{value})) = #{value}"
  else
    attribute + " #{node.value[1]} " + "#{value}"
  end
end

#visit_child_selector(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 122

def visit_child_selector node
  node.value.first.accept(self) +
  '/' +
  node.value.last.accept(self)
end

#visit_class_condition(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 102

def visit_class_condition node
  "contains(@class, '#{node.value.first}')"
end

#visit_combinator(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 106

def visit_combinator node
  node.value.first.accept(self) + ' and ' +
  node.value.last.accept(self)
end

#visit_conditional_selector(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 111

def visit_conditional_selector node
  node.value.first.accept(self) + '[' +
  node.value.last.accept(self) + ']'
end

#visit_descendant_selector(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 116

def visit_descendant_selector node
  node.value.first.accept(self) +
  '//' +
  node.value.last.accept(self)
end

#visit_element_name(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 128

def visit_element_name node
  node.value.first
end

#visit_function(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 4

def visit_function node
  #  note that nth-child and nth-last-child are preprocessed in css/node.rb.
  case node.value.first
  when /^text\(/
    'child::text()'
  when /^self\(/
    "self::#{node.value[1]}"
  when /^(eq|nth|nth-of-type|nth-child)\(/
    if node.value[1].is_a?(Nokogiri::CSS::Node) and node.value[1].type == :AN_PLUS_B
      an_plus_b(node.value[1])
    else
      "position() = " + node.value[1]
    end
  when /^(first|first-of-type)\(/
    "position() = 1"
  when /^(last|last-of-type)\(/
    "position() = last()"
  when /^(nth-last-child|nth-last-of-type)\(/
    "position() = last() - #{node.value[1]}"
  when /^contains\(/
    "contains(., #{node.value[1]})"
  when /^gt\(/
    "position() > #{node.value[1]}"
  when /^only-child\(/
    "last() = 1"
  else
    node.value.first + ')'
  end
end

#visit_id(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 45

def visit_id node
  node.value.first =~ /^#(.*)$/
  "@id = '#{$1}'"
end

#visit_not(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 34

def visit_not node
  'not(' + node.value.first.accept(self) + ')'
end

#visit_preceding_selector(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 38

def visit_preceding_selector node
  node.value.last.accept(self) +
    '[preceding-sibling::' +
    node.value.first.accept(self) +
    ']'
end

#visit_pseudo_class(node) ⇒ Object 



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# File 'lib/nokogiri/css/xpath_visitor.rb', line 84

def visit_pseudo_class node
  if node.value.first.is_a?(Nokogiri::CSS::Node) and node.value.first.type == :FUNCTION
    node.value.first.accept(self)
  else
    case node.value.first
    when "first" then "position() = 1"
    when "last" then "position() = last()"
    when "first-of-type" then "position() = 1"
    when "last-of-type" then "position() = last()"
    when "only-of-type" then "last() = 1"
    when "empty" then "not(node())"
    when "parent" then "node()"
    else
      '1 = 1'
    end
  end
end